Agricultural harvesting heads are devices that are carried to the field to sever a swath of crop plants from the ground and gather the severed crop plants together, either to be returned to the field in a windrow or to be conveyed into a crop harvesting machine.
In a typical arrangement, the crop material is severed by an elongate reciprocating knife that extends across the width of the agricultural harvesting head to sever the crop plants near their roots. The crop plants are then directed onto one or more lateral conveyors that carry them to a central region of the agricultural harvesting head. The cut crop material, now gathered together, is then conveyed rearward by means of one or more conveyors.
One arrangement used to convey the crops rearward is a rotating drum conveyor with protruding fingers. The protruding fingers engage the crop mat and pull it rearward underneath the rotating drum of the rotating drum conveyor. The fingers are attached to a stationary member about which the rotating drum rotates. The stationary member is inside the rotating drum and offset from the rotational axis of the rotating drum. The fingers are supported on bearings mounted on the stationary member and extend through holes in the drum and are a rotated by the drum as the drum is driven in rotation. Since the stationary member is offset, the fingers change their angle with respect to the surface of the rotating drum at the same time that they slide in and out of the drum.
The gap between the holes in the drum through which the fingers extend and the fingers themselves must be small in order to prevent crop material from becoming drawn into the rotating drum as the fingers retract into the rotating drum. In one prior art arrangement, the holes in the rotating drum support spherical plastic balls. These spherical plastic balls have a hole that passes through them that in turn supports the fingers as they slide in and out of the rotating drum. As the fingers change their angle with respect to the rotating drum, the spherical balls accommodate this changing angle by rotating with respect to the surface of the rotating drum (to which they are attached).
This arrangement is prone to wear. What is needed is an arrangement for supporting the fingers at the surface of the rotating drum that is less prone to wear. It is an object of this invention to provide such an arrangement.